Rod wiper for alighting gear



Dec. 2, 1947.

A. P. FALL ROD WIPER FOR ALIGHTING GEAR Filed Nov. 6, 1944 2Sheets-Sheet 1 Dec. 21947. A. P. FALL ROD WIPER FOR ALIGHTING GEAR 2Sheets-Sheet 2 Filed Nov. 6.' 1944 Patented Dec. 2, 1947 UNITED .S TATESPATENT 20F-Fl: CE

ritD-WIPERjFOR ALIGHTING: GEAR 'Albert PJFau, 'roledgfohioApplicationNovember 6, 1944, Serial No. 562,113

3f Claims.

structure. @ThisaDPlicationisza lcontinuationinepart Iof my priorapplication Serial No.

My invention. hasl -tor -itsv principaleobject the ...improvements of.va scraper vfor ..a iv-retractable elf-lighting.- gear. .wherebysuch a;gear is. enabled to withstandfextreme .conditions for-.agreater num--..ber-` of` ying. .hours thanlis the .case with `present structu-res.

5:An.alightingggeariof. the type shown herein by wayof .exam-ple,includes. an upper sleeve,4 the ...upper end-,o'f.which..may bepivotallyattached ...to the-.aircraft .andta lower.. rod, to` .the-bottom .of which ...the ,.axle of .the .wheel .isf attached. iThis`lower rod Ytelescopes..slidingly within the ...upper sleeve with.Ashock...absorbing action. .The .shock absorbing medium .Within thesleeveof. the .strut.structurefisnsually ...oil. or some other sat-`.,isiactory.,solution` .and ythus it. is` necessary that `.an eicient.seal .be .established between the lovver, inside surface.of..the..s1eeve and the outside surface .of the ro'd.

.With the. packingtgland-.structures.utilized vin .the past, .it has-.been .ffound that .considerable difficulty hasV been -.eXper.ienced.when the alight- .ing gear .is .subjected .--to extreme conditions.brought about bythe ggreat distances .that pres- ,ent 1day.. aircrafttravel. The ultimate in a'gpack- Ragland-structure is ...an -assem-blywhich gis capable'. 7oi-w-iping the rodlperfectly clean -as it .slides@within fthe sleeve .to prevent dirt, grit, frost,ice.or.,rnoisturelfr'om-serrating or other- `wise .destroying the.4 `gland and alsoA frompassing throngn the-gland. upwardly into the sleeve.

ftiisanf=important object of the presentinvention to provide animprovedgpacking gland assembly 'which g not only :affords `an ecientsealI for the operating liquid l but f a-lso -eiciently removes:contaminatingmoisture;dirt -or vice from the ;.rod..after @it .is@accumulated thereon, l this .cleaning *operation k.taking placeV`.duri-ng the re- .ciprocation-- of" the-rod. into o the. sleeve andbeing effective 1 upon 4ivery 4.thin ilayers of extraneous,contaminatinggmatter.

one-oi `.ther contributing factors to the diiiiculties whichareaencountered inpresent packingfglands, fisthe;A iactthat .under presentconditionsa planez maya-in., a Tsingle flight; traverse areas.havingigextreme -weather conditions. For instance, a sing-1e .ilightmay .encounter eX- tremely. low .temperatures whereupon frost and1icefaccumulate onthe-rod-and also may. traverse .desert areaseover.Whichi theV air carries-a-con siderable ,percen-tage. of- .sand-:andrgrit. .Previous .eiortshave been. made. -toa remove ice, frost y.andgrit from ,.the rod but it "has Ebeen' -found that `these .struc-turesridea-overthis' .extraneous .-materal -whereb-y itengages1 the sealing.gland :.-to

serrate the same toinitiate-:oil rleakage.

. It -is another .'bject` .of the present invention to provide an\i1nproved :scraper assembly by which thefaccumulated 'ice' is"`efciently. removed `from :thev rodso that itv twill not be forced*`past thegfgland .to `riservate vlthe sisame :andi initiate oil leakagefIt-is .-.sti1l.-:,another':objecteofc the present invention :..tprovide`aan improved; packing .gland as- .-sernbly.;.havingetai.sealing gland;portion andV also 'having 1.a .wiping tforalscraping .Iportion so con-:strnctedfas toaefcientlyut away. ice and frost from the surface of therod as it moves into-the sleeve and yto :remove rg'rit, moisture andyoil from the assurace :vof :the .rod @before :.the wiped forscrapedzsuii ace. entersthrough the sealing. gland portion.

iIt isanother object ofI the present invention to :provide: awiper-#scraperv arrangement-iwhereina w'ipersannulusiispositivelypressed .against the telescopingf rodsol that itW-ill -not ride *overfrost, ice iror. grlit Vparticles"but-willi remove the same 'beforelthelir-d surface slides past a companion vsealinggla-rrd.

'llt is alst-ill'further'objectof my invention to provide an -alighting'gear with-an improved Wip-er portion `rWhich Will facilitate assemblyoi vthe wiperfportionwithout `disassembly 4of the gear.

More specica'lly, it is `an object of the: invention to provide, inapacking gland assemblyfof the above. charente-rfa ,split `Wiper.annulus having arl-'inner'cutting edgeiand an outercompressorcarrier,,groovehousing a resilient compressor Afor urging-`the .cutting Vedge inwardly a'gainStQthe surface ofia'telescoping rodto'be wiped, the.cutting edge thus being positively urged into cuttingengagement .with extraneous matter .on.the.r.o`d.so thatit .will vnotride..over the same .when vtheirod slides thereby.

Many .other yObjects ,andadvantages .of vthe invention willlbecome`apparent from thefollowing .description .and accompanying. drawings inwhich:

IFigure 1 is aperspvectivefview. .of a -landingstrut assembly embodyingthe.;Y features iof -my-invention;

Figure 2 is a cross-sectional View taken on the line II-II of Figure 1;

Figure 3 is an enlarged cross-sectional view taken on the line III- IIIof Figure 2;

Figure 4 is a fragmentary enlarged cross-sectional view of the wiper orscraper ring construction showing the manner of its attachment in theassembly;

Figure 5 is a cross-sectional view of a packing gland assembly for analighting gear which illustrates a modification of my invention;

Figure 6 is an enlarged fragmentary cross-sectional view of thestructure of Figure 5;

Figure 7 is an enlarged cross-sectional view taken along the linesVII-VII of Figure 5;

Figure 8 is a perspective view of the compressor cover of Figures 5, 6and 7;

Figure 9 is an enlarged fragmentary cross-section taken along the linesIX-IX-of Figure 6; and

Figure 10 is a perspective view of a portion of the alighting gearillustrating the method of assembly of my modied wiper structure.

It is to be understood that the embodiment shown herein is forillustrative purposes only and may be changed or modied withoutdeparting from the spirit and scope of the invention as set forth in theappended claims.f

As best shown'in Figure l, the alighting gear shown herein by Way ofexample includes an upper sleeve IG which serves as a compressioncylinder. The upper end of the sleeve or cylinder I0 is provided with ahead II by means of which the entire alighting assembly may be pivotallysecured to the associated aircraft for retraction. As will be seen fromFigure 2, the lower end of the sleeve I8 is open to slidingly receive arod I2 upon the lower end ofwhich is mounted any suitable aXle assemblyI3 for receiving the aircraft Wheel.

To the end that the rod I2 may slidingly reciprocate through the openedlower end of the sleeve I6 and yet will not rotate therein,a collar I4having lugs I5 is provided in non-rotatable relationship around thelower end of the sleeve I. Another similar collar I8 having lugs l'I isprovided at the lower end of the rod I2, these collars being connectedby a torqueY link assembly including links I8 and I9 which are pivotedtogether as at 2E) and are pivoted at their remote ends respectively tothe lugs l5 and Il. Thus it will be seen that upon application ofpressure to the alighting assembly, the rod I2 will be enabled toreciprocate through the lower end of the sleeve I0, the torque linkagemoving to accommodate this reciprocation and at the same time positivelypreventing rotation of the rod within the sleeve li).

From the foregoing it will be seen that some means must be provided inthe mechanism to prevent leakage of oil and thus loss of operatingpressure through the sliding junction of the lower end of the sleeve orcylinder I and the adjacent portion of the outside surface of the rodI2. This is accomplished herein by means of a packing gland assembly 2|which is cylindrical in configuration and is housed within an enlargedportion 22 at the lower end of the sleeve Ill.

The packing assembly is disposed within the enlarged portion 22 of thesleeve and is compressed therein by a nut 24 having an upwardlyextending flange that is internally threaded to engage with externalthreads at the lower end of the portion 22 of the sleeve as shown at 25.The nut 24 is provided at the lower part thereof with a radiallyinwardly extending ange 26, the inner edge of which prescribes a circlehaving a diameter somewhat larger than the outside diameter of the rodI2 which passes therethrough. Thus there is provided between the edge ofthe flange 26 and the rod I2 an annular space available for purposes tobe described presently.

. In order that the packing gland assembly 2I may carry out itsprincipal purpose, that is the provision of a tight, sliding sealbetween the sleeve I0 and the rod I2, a compressible sealing portion 21made up a plurality of segments in the usual manner is provided in theupper part of the enlarged housing portion 22. The packing glandassembly is completed by the provision of an annular bearing member 28which ts within the lower part of the enlarged housing 22 of the sleeveI0 and has an inside diameter of such a size that it slidingly receivesthe rod I2. This packing assembly is maintained in the sleeve as shownin Figure 2 by the attachment of the nut 24 upon the lower end of thesleeve, whereupon the flange 26 thereof is drawn upwardly against thebearing member 28 to compress the yie.dable gland portion 2l into -theposition shown.

As indicated previously, one of the major difficulties encountered inthe construction and use of telescoping alighting gears, is the entranceof sharp particles such as ice, grit and dirt into the sliding junctionbetween the telescoping parts, whereby the sealing gland is cut andserrated and the outer surface of the rod is worn or grooved so that oilleakage is initiated. This condition then progresses more rapidly sincethe leaking oil picks up particles of grit whereby, during furtherreciprocation of the rod, destruction of the seal develops at anincreasingly rapid rate. It has also been found that even a slightcoating of frost upon the outer surface of the rod I2 serves to producethis undesirable condition and accordingly it is necessary to providesome means which will efficiently remove any contaminating matterwhatsoever from the outer surface of the rod and leave said surfaceperfectly clean as it passes through the sealing gland.

To the end there is provided at the lower inside edge of the bearingmember 28 a milled annular groove '29 which is arranged to receive awiper or scraper assembly. It will be noted that since the groove 29 ispositioned at the extreme lower part of the sleeve I0, the wiperassembly therein, to be described presently, will engage the surface ofthe wheel rod I 2, during retraction thereof, before that portion of thesurface so engaged passes along the compressible, destructible sealinggland portionZ'I. Thus the rod surface is cleaned before it passes'thegland and in this manner the introduction of cutting particles ormoisture into the glanded junction by retraction of the rod iseliminated.

The wiper assembly shown herein includes a wiper-scraper annulus 30which is split as shown at 3| in Figure 3. vThe'wiper annulus 30includes a radially inner portion 32 which is provided with a downwardlyprojecting rod engaging, cutting edge 32a and a radially outer portion33 which seats within the bearing groove 29 and is provided with acompressor groove 34 adapted to receive compression means by virtue ofwhich the annulus 30 and particularly an edge 32a thereof is compressedresiliently against the outer surface of the rod I2 with squeeze pressaction. Any suitable compressor means may be utilized, however, there isshown herein an-undulated or sinuous spring steel annulus 35 having adepth substan- 255 ".,tially equal to the `.compressor i: groove i342:inutile fwipen annulus'f, the.:radiallyainwardly:.:extend- Jing. peaksof n whicha press against: thenner @wall of the groove 34 whilezt'he.radially:outeri: peaks thereof press against.lthe;ra;dially.outer lwall:of ,5v5

- theibearing igroove'fZS. Thus ilbwillrbe:- seen. that thecompressoriannulusi urgesithe entire-wiper -annulusl radially .inwardly.withsqueezepressslacationzsothat theze'dge 34a..thereofv bears inwardlyagainst :theouter surface of thezrod I'Ztaszthei .'.latter isretractedinto the `sleevei t0. IThisdirec- Ation ofthe edgeLSZa ofthewiperannulusispw- :.duce'diby a, radialoutward :and upward inclina-Ltion tcfithe radiallynnnerisurface;ofthe annulus 13o as shownfclearlyinzFigur-eifi.

The .aannulus 123i) ...is :maintained v i-nt the 1 bearing `...groove 29by e'ngag'ement Ilof the l:radially :outer parti-33T thereof 'with'. theradially.v inner. portiomof .theJupper .surrfacezioftheiangezonthenut-'24. 'From VFigure 4. itzwillbe .seen that as: the: nuts2-4'.iSJsCreWed onto -the: lower.v end ofthe Asleeve v`III, 'f theilange.is. .drawn `upWardIyuntil it comple- :sments .'.the groove :29 in' thebearing 'to @engage against the radially outertpart'SS: of .thezannu'lusISl. As. .indicated previously, t the l radially inner s edge. of.` theflangelZi onlthe-nut24r isispaced from `the outer wallof rodlzltoaprovide an annular popening. .'Ihis.opening,= as-willberseenfromlFigureflwillbe adaptedto receiveithe radiallyjinner, lower.cuttingredge portion .Loffthe' annulus ,e3

an. with this. Construction. .iti-win be seen .that 'f the flange 26 ofthe nut 24 serves to protect the cutting edge32a of the annulus 30 byvirtue of its extension downwardly beyond that edge. In

this mannerwitvwill "beseen'thatno part of the 7.335

packing :gland assembly .l and particularly the wiping or scrapingannulus thereof.' extends Outwardly of the assembly where itmight besubjected toda'rnage.

It :will be understood ofcourse that whilethego lcompressor groove 34Vshown herein is positioned V substantially, .vertically .central-ly ofthe radially irouterportiont of the annulusf, thisgroove :maybe disposedina position vertically upwardly or `downwardly of thatshown'togive..diflerent compression characteristics,` `as frdesired, depend- 1.ent upon circumstancesencountered inatheause of the `alighting. gear.

From the. foregoing .it .will be. seen that there is provided hereinapacking-gland assembly which,-K includes a resilient sealing portion anda rod cleaning portion, wherebyextraneous matter, accumulated on thesurface of the rod willfrst be removed therefrom by the annulus beforethe surface of the rod is drawn into contact with the resilient sealingportion of the gland.

Also it will be seen that the wiping annulus and particularly thedownwardly and inwardly directed cutting edge 32a. thereof will becompressed inwardly by the compressor 35 housed in the groove 34 so thatthe cutting edge will not ride over extraneous matter on the surface 0fthe rod I2. Instead, the edge 32a will be urged inwardly in a cuttingdirection.

Preferably the annulus 30, when associated with the rod I2, is slightlyspread to permit inward compression thereof against the rod bycompressor 35. This insures the proper amount of pressure of the cuttingedge 32a against the rod and also affords a tight nt of the annulus tothe rod if the latter is slightly out of round or slightly off size.

In the constructions illustrated in Figures 5 through 10, I haveillustrated a modification of my invention in which the alighting gearis profvide'd with oaspacking `assembly in `:whicht'thefwiperrportlomiiasrhadavariousspartstherefesplitioriformedliniztwoepartsiin a-.particularman- :ner=.wvhich#willfbeidescribedrhereinafter soiaseto i-iiaci-litatetheassemblyIthereof withtt-he adighting -gearmfithout ithernecessityeof."disassembling :the ngear.

LfReferringito "Figure 35,;-1 Yrhave f illustrated my :modified 'wiperear-rangementras applied :to the I0 tteiescopirrgemembers f3 t0 :and s I2 :similar to `that `.shown1mFigurei2soflztheriirawings. :Thezsleevertiisizprovidedfwith the :enlargedhousing 22 in rwhichiarefpiacedithepacking 'glandzassemblyl I, -thezeannular :bearing ememberi;28,1and the:..wiper :ning arrangement '40 zyvhich :sis: shown .in anvtenflargedrlietail' yiewtin fFigurelG. "5.'Ihefwiper ring garrangement'.:is placed :in :the rperipherally 'f-extendinggfgroovefil which.acesfthe adjacent-,iserface of the.rddit2," but'itwill' betunderstooduthat :the'ewiper: ringsassemblyiimay lbe placed :in -lanyoother suitable position 1. so :that :it will Lfremove iimpuritiescarriedmn the'fzsurface-fof' the :rod J I 2 -whichzwo1`1zld1inureithepackin'g. gland f2 I if they ewereeallowed.' to remaimonthelouter-surface of 5atherod L2.

.a'lhecwiper .assembly-:as isezshown y.in fFiguresG randi includesiawiperescrapernannulus 4I which :includes .5.a radially inwardlyextending .portion `i42 swlch is :,tprovide'd rwith :a jcutting .edgefor eengaginglagainst the:adjacent'.surfaceof' the rod ;t2.A#The:awip'erfannulus also .fhasoutwardly ex- .ftending'nangexportions43aand'i44'which are.' axlcally spaced.` to iprovide atgroovef 45-iwhich Yis adaptceda-.tofV receiver-accompressorM6. ifIhel .compressormay :be fofaany isuitable type and `in 1 thereonstruction illustrated inthe drawings. there isdneluded n.9, :spring aannulus having aan.lundulated :i shape similar zito i-lthe k1 compressor 235 -shown inr1iigurei3.

order to i facilitate 1 assembly rof l the wiper :ring :around: ther-rodi12, -LwithoutA lremoving 'the rodifrom '"-ithe :member :I0 #a ring l4 Iis-Y provided in two parts 41 and 48-1as isfillustrated'in'Figure `'7.Thus,in order to assemble the-wiper 45 :an-nulusfl Within-the :groove'29, it is not'sneces- -.sary: to remove the' axleassembly I3 -ordisassem- -ble the. links'. I8 and'v ISL-.asA the nut24 need merely T:be`unscrewedI and -moved' axially sufficiently asfis `:illustrated in'Figure 10 so that the'splita-nnulus -maybe inserted in the groove 29.

i Inorder tov facilitate the assemblyvof the semivannular'po'rtions- 41andiA ofthe-wiper ring, -a cover memberf49 'isprovided which may-alsobesplit if desired or provided in two parts 50 and 5I as is illustratedmore particularly in Figures '7 and 8. The half rings 50 and 5I are eachprovided with a channel-shape or have spaced inwardly extending flanges52 and 53.

In order to facilitate the assembly of the two parts of the wiper ringand cover suitable openings may be provided in the halves and pins 54pass through the slotted holes so as to hold the halves together. Itwill be understood that before these anges of the wiper ring portion andthe cover portion are placed contiguous in the manner illustrated inFigure 6, the spring 46 may be placed in the complementary groovesthereof. So that there may be relative movement between the wiper ring4I and the cover, openings in the flanges 43 and 44 of the wiper ringportion are formed as slotted holes 55 as is illustrated in Figure 9.

It will also be seen particularly with reference to Figure 7 that theslits between adjacent ends of the wiper ring portions 41 and 48 and.caught in the spanner slots.

7 between the cover portionsv 50 and 5I'are placed in alignmentlalthough'they may .be staggeredv if desired. It will also be understoodthat the amountcut from the various parts to provide the slits orportions'wll be approximately one-half the amount of lthe cut or slit 3|of the construction illustrated in Figure 3 so that the sum of the twoslits will approximately equalr the value of the slit 3|. When it isdesired to assemble the halves at the factory the compressor ring mayllalso be made in twohalves and each half assembled with the halvesof themain body and cover which are pinned together 'as is shown in Figure 7.Such assembled halves may'then be assemvbled with the alighting gear byunscrewing the nut 26 from the housing '22. vIt will be noted that theadjacentedges of .the complementary parts of'the wiper ring-and covermay-bezinclined as is shown in Figures 7 and 8.

The idea of employing a compressor cover which surrounds the wiper ringand against which the compressor abuts is described and claimed moregenerally in my copending application, Serial No. 561,362, iled November1, 1944. When a cover ring is provided around the wiper ring, the wiperassembly may be placed in a groove in any suitable place such as in thenut even though the nut has open slots for the 'reception of the prongsof a Spanner wrench and the compressor will be maintained in its properposition and there will be no possibility of thecompressor becomingAlso, of course, when the compressor cover is formed of twochannel-shaped members yof the type illustrated in Figures 6 and 7, theassembly of the split wiper ring is facilitated.

Although I have shownand described particular embodiments of myinvention, I do not desire to be limited to the particular embodimentsdescribed, and I intend in the appended claims to cover allmodifications which do not depart from the spirit and scope of myinvention.

-I claim as myzinvention:

1. A scraper or wiper ring assembly for a reciprocating rod comprising ascraper ring having an inwardly projecting scrapingedge and radially`outwardly extending 'axially spaced iianges forming a groove in itsconvex periphery, cover means `comprising a circular member of' channelsection arranged with its flanges lappingthe outer surifaces of the ringanges and vclosing the groove, said scraper ring and cover means eachbeing formed o f two partsfso they maybe 4assembled upon a rodwithoutdisassembly Vof the rod and 'its associated part, a compressor betweenthe scraper ringfandcover member of each of said parts, and

.pins'through lapping parts of the ring and cover means to hold themtogether.

2. A scraper or wiper ring assembly for a re- :ciprocating rodcomprising a scraper ring havingl inwardly projecting scraping edge andradially outwardly extending axially spaced anges forming a groove inits convex periphery, cover means comprising a circular member ofchannel section arranged with its anges lapping the outer surfaces ofthe ring flanges and closing the groove, .said scraper ring and covermeans each being formed of two parts so they may be assembled upon a rodwithout disassembly of the rod and its associated parts, a compressorbetween the scraper ringv and cover member of each of said parts, pinsthrough lapping parts of the ring and coverV means, and said ring andcover means having openings for receiving said pins, the openings-in/said ring being radially elongated so as not to interferewithrelative radial movement of a ring and its cover means.

3. A scraper ring assembly including a resilient ring section having ascraper edge, a cover member having flanges lapping said ring section,pins vthrough the anges and ring section to hold them togethenand acompressor member between 'the cover member and ring section actingagainst the lringsection with squeeze grip action.

ALBERT P. FALL.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS

